Buildpkg is a package build system. It gives you the opportunity
to create package system (like rpm, dpkg, stc.) independent
descriptions (.def) which can be used to
create binary packages on every system. It depends on a few commands / utils
(see requirements), but it is a shell script. No compilcated installation
required. It can be also used to track installations and create packages
of the installed files. If you want more safety, you can use the 'jail'
feature. In this mode a chroot-ed environment will be created from
the (configurable) list of programmes and the installation will be
done here. Supported package formats are : slackware's .tgz (incl. doinst script),
debian's .deb (incl. postinstall), redhat's .rpm (incl. %post) and the
binary only .tar.gz). Besides GNU/Linux, Solaris/SunOS (incl. postinstall) and FreeBSD (incl. postinstall) packages
are also supported.

To read more about its features, take a look into the buildpkg.1 man
page (at the left side)...